Fuse-plug.



R. A. SCHOENBERG. FUSE PLUG.

APPLICATION FILED Nov. II. 1,914.

1,301 ,009, Patented Apr. 15, 1919..

meseta' z-qeyvow UNITED sTATEs PATENT oEEioE.

RALPH ABRAHAM SCHOENBERG, (NOW BY JUDICIAL CHANGE OF NAME RALPH A. BELMONT,) OF NEW YORK, N. Y., ASSIGNOR TO THE CONNECTICUT ELECTRIC MFG. C0., 0F BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

FUSE-PLUG,

Specification of Letters Patent.

Patented Apr. 15, 1919.

Application filed November 11, 1914. Serial N o. 871,609.

To all whom t may concern.'

Be it known that I, RALPH A. SCHOEN- BERG, of New York, in the county .of New York and State of New York, have invented a new and useful Fuse-Plug, of which the following is a specification.

It very often happens when a fuse is blown out that the are is drawn between the two terminals' and one object of my invention is to overcome this defect by providing means which increase the distance between the terminals upon the blowing of the fuse and in the preferred form this separation of the terminals is done automatically andv instantly and to a very great eXtent by an element such as a spring which snaps away from a fixed terminal. Another defect in fuse plugs heretofore has been that when a blow out has taken place no efficient means has been provided to indicate which one of a number of fuses has blown out and I overcome this objection by providing indicating means which are independent of the gases formed on the blowing of the fuse and which act 'efliciently to indicate that a fuse 'has blown and in my preferred form I provide a spring held under tension by the fuse and when the fuse is blown the spring instantly and automatically changes its position and indicates that the fuse has blown.

A feature of my invention consists in providing a member to give such indication by piercing the usual mica disk and this member may be a pin yor equivalent device carried by the above-mentioned spring and it is desirable in many cases to have the pin insulated from thev spring so as to prevent y a shock to any 4person touching the protruding pin in case, for example, such personwere standing on a metal or damp floor.

In the accompanying drawings:

Figure 1 is a central longitudinal sectional view of a fuse plug construct-ed in accordance with this invention ;A

Fig. 2 is a section on line 2-2 of Fig. l; and

Fig. 3 is a sectional'view illustrating another form. Y

Having reference to the drawing 1 repre sents the body of my improved fuse plug, said body being made with an interior chamber Q within which is arranged the fuse wire 3. The fuse wire 3 is soldered at one end to a terminal which is the center contact -l of the plug and at its opposite end to another terminal being soldered to one end of a metal spring indicator member 5 fastened by solder or otherwise to the threaded metallic shell of body l. The top wall of the plug consists of a thin transparent sheet or disk of mica 6 immediately beneath which the member 5 is arranged, and the latter has attached thereto a pointed pin or spear 7 disposed with its point toward the thin mica wall 6.

The spring indicator member 5 is held under tension by fuse wire 3 and when the latter is blown or burnt out the member 5 snaps toward the mica sheet 6 driving the prong 7 through said mica. Thus when a set ,or group of plugs is being examined to locate the blown plug, the mere change of position of the spring will indicate that'the fuse has been blown and the prong protruding from the mica sheet is also a tell-tale or indicator by means of which the blown fuse may be quickly located. I

I prefer to provide an insulatinv washer 8 between the member 5 and prong? so that the latter will not be electrically connected with the outside screw-threaded metallic shell of the plug. This makes it impossible for one to receive a shock from contact with prong 7 while removing the burnt out plug.

In Figs. 1 and 2 the spring indicator member 5 is a straight arm of sheet metal while in Fig. 3 I have shown a helical spring member 5a.

It will be clear that when the fuse blows the spring member will instantly and automatically move to the position shown in dotted lines so that the distance between the terminals will at once be increased by the distance from the point 51 to the point 52 and in this way arcing will be effectively prevented.

The shell 1 is formed with exterior screw threads so that the plug can be screwed into a socket in the usual fashion. The inner end of shell 1 is made with an inturned flange 21 that is formed witlrfour crimps 31 which provide as many elevated seats upon the inner side of said flange and four radial channels or grooves upon the out-er side of said flange. The four seats pro- A vided by the crimps 31 support a washer 41 of non-brittle insulating material, preferably compressed fiber, provided with a central aperture. and peripheral notches 61. The central aperture accommodates the center contact 4 of the plug which, at its outer end Ahas mounted upon it a washer 81 of non-brittle insulating material, preferably compressed fiber, that is held in positionagainst the outer side of flange 21 by the head 9 of contact 4. The shank of contact 4 consists of two prongs l0 which are bent or upset so as to clamp washers 41 and 81 firmly to flange 21. l/Vithin theshell 1 is arranged a lining 11, of non-brittle sheet material, preferably compressed fiber, that snugly fits the interior of shell 1 and within which the washer 41 fits snugly. This lining 11 is made from-a strip of sheet material of the character specified, formed at one corner with a notch for spring 5 and rolled into cylindricalform.

When the' fuse burns out the gases are free to pass out of shell 1 through the notches 61, the space 14 betweenwasher 41 and flange 21 the aperture `surrounded by fiange 21 and tliechannels provided upon the exterior of the latter by crimps 31;' y1

Near its outer end the shelll is made with an annular crimp which provides a shoulder against which a ring 17 is clamped by an out-turned fiange 18 at the outer end of shell 1. This ring 17 -is of non-brittlein sulating material, preferably compressed fiber. AA disk 6 of -mica or other suitable transparent insulating .material iS placed' against said flange and held in-place by a metal ring 19 surrounding said disk and ring 17, said metal ring having at its outer end an inwardlyextendingflange 20 bearing against the outer side of disk 6 and bing turned or crimped inwardly against ring 17 asi-,at 22 so that the disk 6, flange 18, ring 17 and ring 19 are clamped securely together and cannot be rotatively displaced relatively when ring 19 is grasped and rotated to insert the plug in its socket or remove it therefrom.

I lhave above described a very desirable form of fuse plug body but it will be clear that any suitablebody may be used.

What I claim is:

1. A fuse plug comprising a screw shell;

an air chamber; a vent for said chamber a fuse in said chamber; terminals connected by the f use, one of said terminals being connected to the-shell; and means to increase thedistance' between said terminals upon the blowing of the fuse.

2. 'A fuse plug comprising a screw shell contact member; a 'center contact Amember;

a fuse; and a self-active means held inactive by the fuse, ,said 'fuse and means connecting said members and increasing the distance between said center contact member and said self-active means upon the blowing of the fuse to indicate that the fuse has blown.

8. A fuse plu screw shell mem er; a center contact member; a fuse connected to one of said members; a spring terminal connected to the fuse and also to the other of said members, said spring terminal being held in abnormal position by the fuse but returning to normal position on blowing of the fuse and thereby increasing the distance between said spring terminal and that member to which said fuse is connected.

4. A fuse plug comprising a .screw shell body member; alining for said member; a center contact; a fuse; terminals connected by the fuse, one of said terminals being the center contact and the other a spring held in abnormal position vwhen connected to the fuse but returning to its normal position upon 'the blowing of the fuse to increase the distance between said terminals.

.5. A fuse plug comprising a conducting screw shell; a spring indicator terminal di.- rectly connected to the shell; a second terminal; and a fuse connecting the two terminals, said spring indicator terminal acting upon the blowing of the fuse to increase the distance between the terminals.

6. AA fuse plug comprising a screw shell; a center contact; a fuse connected to said contact; a self-active terminal for said fuse which is `directly connected to said shell; and means carried by said terminal to indicate when the fuse has blown.

7. A vfuse plug comprising a body; a chamber within said body; aself-active terminal 'within said chamber; a fuse to hold said terminal inactive; and an indicating portion' insulatively attached to said termina-l to inf dicatethat said fuse has blown when said blowing releases the terminal.l

8. A fuse plug comprising a screw shell contact; a center contact; a self-active terminal and a fuse to directly connect said comprising a conducting sol contacts; said terminal being heldl inactive i by the fuse and released 'on blowing of the fuse to indicate :that the fuse has blown` 9. A fuse plug comprising a conducting screw shell; a transparent cover; a center contact; a fuse connected to said .'contact; a

,spring connected at one end to the shell and at theV other to the fuse, said spring being 11. Ause plug comprisin a fuse chamber; a fuse in said cham r; a. spring normally held under tension by the fuse; a pin carried by the spring bu-t insulated therefrom; and a mi'ca sheet closing said chamber, said spring acting to force said pin to penetrate said sheet.

12. A fuse plug comprising a shell; a fuse chamber; a fuse in Said chamber; a sprin electrically connected to the shell and held under tension by the fuse; a. pin carried by the spring; and a micasheet closing said chamber, said spring acting upon the blowing of the fuse to force said pin t'o penetrate sald sheet.

13.v A fuse plug comprising a screw shell body member; a lining for said member; a chamber within said lining; a cover for said chamber; means to attach said cover, said means being insulated from the shell body member; a fuse; a terminal for said fuse directly attached to said shell body member; a center contact member; and an insulating support for attaching said center contact member to said shell; said fuse and terminal electrically connecting said members.

14:. A fuse plug comprising a screw shell body member; a; tubular lining for said shell; a fuse; a fuse terminal connected to said shell; a center contact at one end of the plug connected to said fuse; an insulating support for attaching said center con-tact to said shell; a cover for the other end of the plug; and metallic means insulated from the conducting member to connect said cover to said plug.

15. A fuse plug comprising a screw shell body member; a cover therefor; means to attach said cover to said body member; a fuse; terminals electrically connected by the 17. A `fuse plug comprising a shell contact; a vented fuse chamber; a center contact at one end of said chamber; a fuse withinthe chamber; terminals connected by the fuse; means to increase the distance between the terminals on blowing of the fuse; and an indi-rect gas outlet at the center contact end of the plug.

18. A fuse plug comprising a screw shell body member; a non-brittle insulating lining therefor; a center contact; a plurality of spaced washers connecting said center con-l tact with the screw'shell body; a cover of` insulating material; a hand hold; a sprin terminal connected'to said shell body an carrying a pin; and a fuse connecting said center contact and said terminal, said spring terminal acting on the blowing of the fuse to increase the distance between said center contact and said terminal, said pin eXtending outside of the plug on the blowing of the fuse to indicate that the usehas blown.

RALPH ABRAHAM SGHOENBERG.

YWitnesses:

LEON STRAUss,

ABRAHAM L. BUSH. 

